How to Change a Bike Cassette: Tools, Lockring Torque and Freehub Bodies

To change a cassette you need a 12-spline lockring tool, a chain whip and a large wrench. Loosen the lockring while holding the cogs with the chain whip, slide the cassette off, slide the new one on lining up the wide spline, and tighten the lockring to 30-50 N·m (Shimano) or about 40 N·m (SRAM). The hard part isn’t the wrenching, it’s buying the right cassette: it has to fit your wheel’s freehub body (the splined part of the hub it mounts on) and match your derailleur and chain.

When it’s time to replace it

A cassette wears more slowly than a chain. If you replace chains on time (at 0.5% elongation on 11- and 12-speed, 0.75% on 10-speed or fewer), it usually lasts two or three chains. The clear sign is that a new chain skips on the cogs you use most when you push hard on the pedals. We go into more detail in the guide on when to replace your chain.

Other reasons to change it: easier gearing for the mountains (see how much you gain in the guide to the best gearing for climbing) or switching to a different wheel.

Which cassette fits your wheel

Check the freehub body before you buy. These are the main ones:

The essentials, according to Shimano’s October 2026 compatibility chart and SRAM support:

• Shimano 12-speed road (Dura-Ace CS-R9200, Ultegra CS-R8100, 105 CS-R7100 and CS-HG710): fits the 11-speed road freehub (HG L, 36.75 mm long) and the dedicated 12-speed one (HG L2, 37.65 mm). It does not fit an HG M freehub.
• Shimano 12-speed mountain: Micro Spline freehub, which takes nothing else.
• SRAM road AXS: almost all need an XDR driver, which is 1.85 mm longer than XD; you can fit an XD cassette on an XDR driver with a 1.85 mm spacer behind it. The exception is the XPLR PG-1231 (11-44), which fits a Shimano 11-speed road HG freehub.
• Cassettes with a 10-tooth cog: they don’t fit an HG freehub, which is why XD, XDR and Micro Spline exist.

If your wheel accepts several freehub bodies, you often only need to swap the freehub, not the whole wheel. The freehub body chart has more dimensions and spacers, including Campagnolo.

Besides the freehub, the cassette must have the same number of speeds as your derailleur and shifter, and its largest cog can’t exceed what the derailleur handles (Shimano lists it as “max low sprocket”). Shimano also says to use its 12-speed cassettes with its 12-speed chains (CN-M9100, M8100, M7100 or M6100), because other chains don’t match the dimensions.

Tools

The Shimano and SRAM tool is about 23.4 mm in diameter; Campagnolo’s is about 22.8 mm. They look the same, but one doesn’t work for the other.

How to remove a cassette step by step

1. Remove the rear wheel with the chain on the smallest cog.
2. Fit the lockring tool into the lockring. With a quick-release axle, Park Tool suggests reinstalling the skewer and snugging it against the tool so it can’t slip out.
3. Wrap the chain whip around a large cog, pulling in the direction the wheel turns forward.
4. Put the wrench on the lockring tool: with the chain whip at 9 o’clock and the wrench at 3 o’clock, push both down. The wrench turns counterclockwise. A loud crack as it breaks free is normal (it’s the teeth on the lockring).
5. Unscrew the lockring and slide the cogs off carefully. Note the order and orientation of the spacers.

Installing the new cassette

1. Clean the freehub body and check it doesn’t have deep gouges from the cogs. If it does, some cogs won’t seat properly.
2. Add the spacer you need, if your freehub and cassette combination calls for one (for example, 1.85 mm for a 10-speed cassette on an 11-speed freehub).
3. Line up the wide spline on the cassette with the wide groove on the freehub. It only goes on one way. Markings on the cogs face out.
4. Slide the cogs on in order, largest to smallest, with their spacers. Shimano warns that on 12-speed Dura-Ace and Ultegra the two spacers have different thicknesses: don’t swap them. On the smallest cog, line up its inner tab with the slot in the second cog.
5. Grease the lockring threads and thread it on by hand.
6. Tighten to spec: 30-50 N·m (266-443 in-lb) on Shimano, about 40 N·m (354 in-lb) on SRAM XD, or whatever your manufacturer says. You don’t need the chain whip to tighten: the freehub locks in that direction.
7. Install the wheel, check the shifting and run through every gear.

Shimano warns that if you tighten with the cogs out of position, the splines can be damaged and the wrench can slip suddenly. If the lockring doesn’t thread on smoothly, stop and check.

Lockring torque specs

For the rest of the bolts on your bike, the bike torque chart lists values by brand.

After you change it

• Readjust the rear derailleur. With a different wheel, the cassette sits in a slightly different spot; and if the largest cog changes size, so does the B-tension. We explain it in the guide on how to adjust a rear derailleur.
• Check chain length if you’ve moved to a bigger largest cog: the chain length calculator tells you if you need more links.
• Check the gearing you gain or lose with the gear ratio calculator.

Common mistakes

• Buying a cassette without checking the freehub. It’s the most expensive mistake: a cassette with a 10-tooth cog won’t fit an HG freehub.
• Forgetting or doubling the 1.85 mm spacer. If it’s missing, the lockring doesn’t clamp the cogs and they rattle; if there’s one too many, there isn’t enough thread.
• Turning the wrench the wrong way when loosening. It loosens counterclockwise, looking at the wheel from the cassette side.
• Tightening by feel. Too loose and the lockring backs off and the cogs gouge the freehub; too tight and it’s hard to remove next time.
• Installing a new cassette with a worn chain. It will skip and you’ll wear the cassette out early. Replace both together if the chain is past its limit.

Updated October 19, 2026 ·Report an error on this page